Drawing sheet glass



A Dec. 15, 1925- l J. c. BLAIR vDRAWING SHEET GLASS Original Filed Dec.26, 1.923

Patented Dec. 15, 1925.

UNITED STATES 1,565,307 PATENT OFFICE.

JAMES C. BLAIR, O F TOLEDO, OHIO, ASSIGNOR T0 THE LIBQBEY-OWENS'SHEETGLASS COMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO.

DRAWING SHEET GLASS.

Application led December 26, 1923, Serial No. 682,612.

To ad elm/m, t may conce/m.'

lie it known that I, Jarras C. Bharu, a citizen oi' the United States,residing at Toledo, in the county of Lucas and State of Ohio, hareinvented new and useful Improvements in Drawing Sheet Glass, ot whichthe following is a specification.

This invention relatesto improvements 1n the art of making sheet glass,and more particularly to the art or iiowing molten glass down a guidingor supporting slab and drawing this glass downwardly from the slab insheet form.

-The present improvement relates to the use in such a. sheet producingsystem of auxiliary drawing and guiding means acting only upon the edgeportions of the sheet. These means will ordinarily be in the form ofpairs of rollers between which the edge portions otI the sheet aregripped. Rollers of this type, `it'or performing a somewhat similarfunction with an upwardly drawn sheet are disclosed in certain patentsheretoiore granted to I. WV. Colburn, for example, Reissue Patent No.14794, granted January 2'?, 1920.

These edge rollers are preferably driven at a peripheral speed somewhatslower than that of the main sheet drawing means, and will function toassist in moving the normally slower and more sluggish edge por tions ofthe iiowing streams down and from the supporting slab. The rollers alsofune tion to exert a retarding and supporting actionon the edge portionsot' the sheet be low the slab and between the slab and the main sheetdrawing means. The combined result is to counteract the tendency of theflowing streams, and also of the formed sheet, to become narrower as thesheet is vcontinuously drawn from th'e slab. TheseedEe V'e rollers alsoact to cool and strengthent edge portions ot' the sheet, and act as anad-4 ditional guide and straight-edge below the supporting slab, whichprevents wobbling of the, forming sheet, thus assuring a Hatter linishedproduct. Furthermore, with a down-flow device of the type here shown,wherein two converging streams of glass meet at the lower edge of awedge-sha ed slab, the use of these edge-holding rol ers beneath the'slab aids the natural adhesion of the molten glass and the refractoryslab in keeping the streams against the inwardly Renewed February19,-,1925.

description oi one form of apparat-us cnr,

bodying the principles ot' this invention.

In the accompanying drawings: p

Fig. l is a perspective, partiallyin section, illustrating the use oi"edgfrholding rollers with one forni of sheet-producing apparatus.

Fig. 2 lis a longitudinal central section through one oi' the rollers,illustrating the cooling means therefor.

The molten glass l 4flows downwardly through the slot 2 in the bottom 3of the tanl: or furnace into a recess 4 in the upper end ot' arefractory supporting slab or directing member- 5. The molten 'glassoverflows or spills from the recess 4 over the upper edges 5 or' theslab and flows in thin equal streams 6 down the opposite converging ilatfaces of the slab. Thesey streams ilow together at the lower edge 7 fthe slab and the glass sheet 8 is drawn downwardly from these combined'streams by the, weight of the. formed sheet assisted by any. suitableform of drawing mechanism such as the present disclosure i'or `the sakeof clear- I ness.

The drawing mechanism is here shown in the form of a plir of driven belt`loops 10 between the downward runs of', which the sheet is gripped. Itis to be understood that this merely illustrates one torni of drawingmeans that might be used. lThis drawing means should be located-farenough beneath the sheet source to allow the sheet surfaces to becomecooled and set so that the likelihood of injury thereto from contactwith the drawing means will be reduced to a minimum. .l

l At each-edge ofthe sheet,directly beneath the lower edge 7 of slab 5,Where the sheet irst takes form, is located a pair of small ineens fordrawing awe-y meinem @e sheet.' oi'nx, and pairs of roiiere edge porionsonly of the sheet line of formaion of the sheet.

9. in apparatus for producing sheet glass. e. source einleiten glass, eWedgeehepeci sieb down ine opposite converging sides of Wiiioii themoiten giese ows fljom the source, the glass formed fiom theseconverging Streams in single sheet form, and pairs of driven roiersengeging the edge portions only of the sheet adgeeen' ehe line offormation of the sheet. l0. in apparatus :for producing Sheet glass, egoeroe of molten less, e slab or forming member down whie glass ows fromthe Source, means for drawing this giass from the sieb in sheet forni,and 'rotary guiding means engaging only the edge portlonsof che sheet,-adjacent the sheet source.

11. in ep eratusfor e source o molten glass, e wedgeshaped sieb-down theopposi''fe converging sides of which the nioten vgaos Hows fromthesouzqee, meens'er drawing away the glass follned converging. eireeinsin single sheet forni, and 'rotary guiding means eneneeging theeiiajacent the seuice. giaes apparatus, a s ouree of producing sheetgloss,

CioWn vW'iiieioglass iews from the eonice, means for drawing this glass@vom ehe vSieb -n sheet form,y and; means for reiarciing movement oftheedge portions of the shee being drawn.

13. In sheet glass apparatus, a eouree of limiten giass, a sieb' orforming member down which glass Hows from the source, means for drawingthis glass from the sieb in sheet form, and means for supporting andz'etar'ding movement of the edge portions of th'e sheet being drawn 4tomaintain the sheet to Width.

14.-. In sheet 'lass appaia'ius, a Sieb, means for fiowng mo ten glassdown both sides of the slab, means for drawing the streams from theendof the .slab in united sheet form, and means for forming e knuriededge on seid sheet..

l5. In sliee't giaes apiemtue, e sieb, means for forming molten g assown both. sides hereozf, means for firwing the streams from the end ofthe sleb'in united sheet form, and knulied 'relis engaging the edges ofi'-he sheet for formingimuried edges heie'on.;

'sel

Si ned at- Toledo, in the county of Luces and btate of Ohio, this 17thdey of )December, 1923.

JAMES e. BLAIR.

